Quick Summary
HTW-FC24-4KEN is a Modbus thermostat for fan coil unit projects that need local room control and RS485 communication. It supports 3-speed fan control, 2-pipe or 4-pipe FCU systems, and configurable on/off or modulating valve control. It can manage heating and cooling conditions, while also supporting external sensor, keycard, and 2-stage cooling options.
This page explains how this hvac thermostat works in real FCU projects, not only what functions it has. It covers the control value of each function, system logic, key technical parameters, wiring confirmation, common project questions, and possible OEM or ODM customisation. It is written to help us choose the right model before ordering.
Key Functional Highlights
(This section introduces the main control functions of this Modbus thermostat and their engineering value in the specific hvac system.)
(1) 3-speed fan
The 3-speed fan output helps match common FCU projects with low, medium, and high fan speeds. This makes room comfort easier to control in hotels, offices, apartments, and light commercial rooms. It also helps maintenance teams keep a clear and familiar control logic.
(2) 2/4 pipe configurable control
HTW-FC24-4KEN supports 2-pipe and 4-pipe fan coil systems, which gives one model wider project use. The valve control can be configured for on/off or modulating control, depending on the system design. This helps us avoid selecting different platforms too early.
(3) External sensor or keycard
The external sensor option is useful when room temperature should be measured away from the thermostat body. The keycard option is often helpful in hotel rooms, where energy saving matters after guests leave. These options help the Modbus thermostat fit different project habits.
(4) RS485 Modbus
RS485 Modbus allows the thermostat to connect with a building management system or central controller. This is useful when an hvac project needs monitoring, parameter reading, or group management. It helps reduce manual checking across many rooms.
(5) 2-stage cooling function
The 2-stage cooling function supports projects that need stronger cooling control than a simple single-stage output. It can help improve comfort where cooling demand changes quickly. It should be confirmed with the actual FCU design before final model selection.
If one is also looking for the Wi-Fi feature, or needs a thermostat controlling EC fan/0-10V valve, one may refer to this all-in-one design instead (HTW-FC24-Altra).
Product Design and Display
(This section shows the thermostat appearance, screen interface, and installation dimensions of this specific Modbus thermostat model.)
Technical Specifications
(This section lists the key technical parameters relevant to this hvac thermostat model.)
| Parameter | Value |
|---|---|
| Power Supply | 24V or 100~250VAC, 50/60Hz |
| Current Load | Fan/Valve Relay 5A; 3A inductive |
| Sensor Support | Built-in Sensor NTC3950 10K, External Sensor, Humidity Sensor |
| Temperature Accuracy | ±0.5°C or ±1°F |
| Set-Point Range | 5~35°C |
| Communication | RS485 Modbus |
| System Type | 2-pipe or 4-pipe FCU |
| Warranty | 2 Years |
Wiring Diagram
(This section provides the wiring diagram for this Modbus thermostat in the relevant hvac control system.)
【Image 4｜Diagram】
Example HTW-WF11-FC-xx: if xx = 2EN, it stands for a 3-speed fan, 2-pipe system with on/off valve control, external sensor function, and Modbus communication. Most sub-models are ready-made. Kindly contact us to confirm availability.
Project Fit & Customization
(This section describes project suitability, system limitations, and available customization options for this hvac control application.)
HTW-FC24-4KEN is not suitable for projects that need WiFi app control as a standard function. It is also not the best choice for systems that need direct boiler dry-contact control, electric floor heating, or heat pump logic. Before ordering, we should confirm the FCU type, valve signal, voltage, and BMS requirement.
Despite these limitations, we can discuss ODM function customisation for some project needs. For example, WiFi, different communication logic, special sensor use, or changed default settings may be reviewed. These changes depend on order quantity, hardware space, firmware work, and testing time.
OEM customisation is also available for brand and market preparation. This can include logo printing, front panel marking, colour customisation, label, packaging, manual, and model code. Please feel free to get in touch with us before confirming artwork or packaging files.
Certificates and Compliance
(This Modbus thermostat complies with European market requirements and is supported by certifications such as CE, RoHS, LVD test reports, EMC test reports, etc.)
Exhibition Moments
(Our team regularly participates in international HVAC exhibitions such as Febrava in Brazil, The Big 5 in Dubai, and ISK-SODEX in Turkey, etc.)
Frequently Asked Questions
Q1: Can HTW-FC24-4KEN be used for both 2-pipe and 4-pipe FCU systems?
Yes, it can support both 2-pipe and 4-pipe fan coil systems. We still need to confirm the valve type and control signal before ordering. This helps avoid wiring or control mismatch on site.
Q2: Does this model support BMS communication?
Yes, it supports RS485 Modbus communication for BMS or central control projects. This makes it suitable when the building needs room data or central parameter management. Please confirm the register list before project use.
Q3: When should we use an external sensor?
An external sensor is useful when the wall position does not show the real room temperature. It can also help when airflow or sunlight affects the thermostat body. Sensor placement should be checked during installation.
Q4: Can the keycard function be used for hotel projects?
Yes, the keycard option can support hotel energy-saving logic. It helps control the room condition when guests leave. The exact control action should be confirmed with the project wiring design.
Q5: Do you support samples and what is the MOQ?
Yes, we support samples for project checking. The usual MOQ is 300 pieces. Smaller trial orders, such as 100 pieces, can also be discussed.
Q6: How can we place an order and arrange payment?
Please feel free to get in touch with us to confirm the model, function, and quantity first. We can then provide a PI for confirmation. Payment can be made by TT, PayPal, Visa, and terms such as EXW, FOB, or DAP.
Q7: How long does it take to prepare the products?
Non-customised samples are usually sent within 7 days. Customised orders need project review, programme changes, and testing, usually taking 3 to 5 weeks. A 300-piece batch usually needs about one month.
Q8: How do you ship the products?
For samples and small orders, express delivery is usually recommended. FedEx, DHL, or UPS can often deliver door to door in about 7 days. Air freight takes about 7 days, while sea freight usually takes over one month.
Need Help Choosing the Right Model?
Please feel free to get in touch with us. We can help check the FCU system, wiring, voltage, and communication needs.
Related Thermostat Models
For more details, please click here directly: Wi-Fi Thermostats | Modbus Thermostats | BACnet Thermostats
Final Note
HTW-FC24-4KEN is a practical choice when local FCU control and building communication are both needed. The key is to confirm the system type before discussing appearance or branding. For stable project use, we should check voltage, valve logic, sensors, and communication early.
